Electrodynamic Print Head Shielding Electrodes Ink Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrohydrodynamic print heads face challenges in achieving effective lateral ink deflection due to complex wiring requirements and limited aperture, which can lead to ink hitting the well walls and flooding, especially when using segmented extraction electrodes.
Innovation Solution
The print head incorporates multiple shielding electrodes at different angular positions around each well, allowing for efficient lateral ink deflection by shaping the electric field over a larger volume, with subsets of interconnected electrodes simplifying wiring and enabling uniform deflection across multiple nozzles, and ventilation openings to manage gas flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If segmented extraction electrodes are used for lateral ink deflection, then lateral deflection capability is improved, but wiring complexity increases due to multiple independent potentials required at each nozzle
Solution Approach 1:
The shielding electrode is segmented into multiple independent segments (e.g., 4 segments) that can be controlled independently. This allows lateral deflection of ink without requiring complex wiring at each nozzle, as the segmentation is implemented in the shielding electrode rather than the extraction electrode. Each segment can be assigned different potentials to achieve precise lateral deflection control.
Solution Approach 2:
The shielding electrode is given a dual function: it continues to provide field shielding to prevent crosstalk between adjacent nozzles, and simultaneously provides lateral deflection capability through its segmented structure. This multi-functionality eliminates the need for separate deflection electrodes, simplifying the overall wiring architecture while maintaining both shielding and deflection functions.
2Adaptability or versatility
If extraction electrodes are used for lateral deflection, then deflection is achieved, but the effective aperture is limited by the well diameter-to-depth ratio
Solution Approach 1:
The shielding electrode is divided into multiple segments that extend laterally beyond the well diameter. This segmentation allows the deflection field to act over a larger effective aperture than the well diameter would suggest, enabling lateral deflection of ink as it exits the nozzle and travels through the broader region between print head and target.
Solution Approach 2:
The shielding electrode segments are positioned and dimensioned to create a deflection field that extends in the lateral dimension beyond the confines of the well structure. This dimensional extension allows the electric field to influence ink trajectories over a larger area, effectively increasing the aperture beyond the well diameter limitation.
3Productivity
If lateral asymmetry in extraction electric field is present, then ink extraction is achieved, but meniscus shape distortion occurs leading to lateral droplet extraction and potential well flooding
Solution Approach 1:
The shielding electrode acts as an intermediary element that shapes and balances the overall electric field. By applying appropriate potentials to the segmented shielding electrode, it compensates for lateral asymmetries in the extraction field, maintaining meniscus stability while allowing effective ink extraction to proceed.
Solution Approach 2:
The potentials applied to the segmented shielding electrode are dynamically adjusted to balance the lateral electric field components. By changing these potential parameters, the system maintains meniscus stability during extraction, preventing lateral droplet extraction and well flooding while preserving extraction efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances ink deflection efficiency, reduces wiring complexity, and minimizes ink flooding by covering a large circumference of each well with shielding electrodes, allowing for precise and high-resolution printing without the need for complex mechanical movements.
Implementation Method 1
The shielding electrode reduces crosstalk between the nozzles and maintains a homogeneous electric field between the print head and the target. In one embodiment, the extraction electrodes are split into two or three segments, which are operated at slightly different voltages for laterally deflecting the ink.
Implementation Method 2
WO 2016/120381 describes an electrodynamic print head having a plurality of nozzles located in a plurality of wells. Extraction electrodes are located around the wells at a level below said nozzles. They are used to extract ink from the nozzles.
Data Source
AI summary
An electrohydrodynamic print head has a plurality of nozzles arranged in a plurality of wells. Extraction electrodes are located around the wells at a level below the nozzles. Further, shielding electrodes are located around the wells at a level below the extraction electrodes. For each well, there are several such shielding electrodes located at different angular positions. This allows to use the shielding electrodes for laterally deflecting the ink after its ejection from the nozzles.